Ore bodies are typically processed by mining the ore body and transporting the mined ore to a processing plant. After concentration and further processing of the ore, there is often a large volume of waste material such as tailings which remain to be disposed of in an environmentally acceptable manner. Thus, there are two particular areas in which the mining and processing of ores may be improved, namely, the reduction in the amount of transport required to deliver the ore from the mine site to the processing facility and the provision of a suitable means of disposing of the wastes.
Both of these improvements can be achieved by having a processing facility which is transportable so that it can be moved as required so that it will always be located relatively near to the site where the ore is being mined. By locating the treatment facility near the mining site, those areas of the mine site which have already been dug out may provide a ready dump for the waste material.
Bearing in mind that many mine sites are underground, it would be highly desirable for the processing facility to be dimensioned so that it can be readily transported underground to be located close to where ore is being mined, e.g. in the underground drive of a mine.
Overall, some of the potential benefits of underground processing are identified as follows:—                step change reduction in ore transport costs;        possible reduction in material losses due to repeated handling and transportation operations;        noise suppression;        reduced surface dust;        reduced operating costs;        reduction in total capital costs when transport systems and processing systems are assessed as a whole;        reduced demand for ore and waste haulage capacity;        increase in mine output. (Note: many mines have limitations imposed by the current capacity of the shafts or declines that exist—underground concentration of feed should help to alleviate such bottlenecks).        
The benefits of such a system may be particularly marked in relation to where the ore body can be greatly pre-concentrated. This is the case in the gold sector and is particularly applicable where the mining of the ore body is heading towards a depth of 500 metres and beyond.